21161004043223 has 16 divisors (see below), whose sum is σ = 24442805993760. Its totient is φ = 18105561600000.

The previous prime is 21161004043183. The next prime is 21161004043229. The reversal of 21161004043223 is 32234040016112.

It is a cyclic number.

It is not a de Polignac number, because 21161004043223 - 2¹⁸ = 21161003781079 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161004043229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50173223 + ... + 50593223.

It is an arithmetic number, because the mean of its divisors is an integer number (1527675374610).

Almost surely, 2^{21161004043223} is an apocalyptic number.

21161004043223 is a deficient number, since it is larger than the sum of its proper divisors (3281801950537).

21161004043223 is a wasteful number, since it uses less digits than its factorization.

21161004043223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689458.

The product of its (nonzero) digits is 6912, while the sum is 29.

Adding to 21161004043223 its reverse (32234040016112), we get a palindrome (53395044059335).

The spelling of 21161004043223 in words is "twenty-one trillion, one hundred sixty-one billion, four million, forty-three thousand, two hundred twenty-three".